WO 00/45983 A1 discloses a mounting device of the type referred to for clamping a toolholder, in which a base unit attached to a machine spindle driven for rotation about an axis of rotation includes a receiving opening centrally located with respect to the axis of rotation and adapted to receive axially therein a coupling shaft of the toolholder of circular cross-section. The receiving opening is provided with mating surfaces suitable for engagement with complementary counter-mating surfaces of the coupling shaft. Arranged in the receiving opening is a collet which acts on the coupling shaft and is actuatable by a collet actuator axially adjustably guided relative to the base unit.
Holding pins of rotary bodies which serve to receive the rotary bodies during balancing are frequently part of a torque-transmitting shaft-to-hub connection and may be provided with a polygon profile for the purpose of torque transmission. One application example of a polygon design of holding pins are polygonal hollow tapered shanks with plane contact surface to DIN-ISO 26623. Polygonal hollow tapered shanks enable precise location and axial positioning as well as precise angular positioning in the receiving opening on the spindle of a machine tool, which receiving opening is provided with a mating polygonal hollow shape.
Tools rotating at high rotational speeds are generally balanced in a balancing machine in order to avoid undue loads on the machine tool's spindle caused by unbalance, and impairment of the machining quality. The demands placed on the balancing quality of such tools are high and require precise, centered clamping of the tools to be balanced or of the toolholder carrying them in the mounting device arranged on the spindle of the balancing machine.
For the mounting of holding pins provided with a polygon profile, for example, tools or toolholders having a polygonal hollow tapered shank, in a balancing machine, mounting devices are known having a receiving opening provided with a mating polygonal inner contour. In view of the high accuracy demanded for precise, accurately centered mounting, the manufacture of such mounting devices equipped with the appropriate polygonal inner contour is very expensive.